%0 Journal Article
%T Disentangling stellar activity and planetary signals
%A Boisse I.
%A Bouchy F.
%A H¨¦brard G.
%A Bon£¿ls X.
%J EPJ Web of Conferences
%D 2011
%I 
%R 10.1051/epjconf/20101102005
%X Photospheric stellar activity (i.e. dark spots or bright plages) might be an important source of noise and confusion in the radial-velocity (RV) measurements. Radial-velocimetry planet search surveys as well as follow-up of photometric transit surveys require a deep understanding and precise characterization of the e ects of stellar activity, in order to disentangle it from planetary signals. We simulate dark spots on a rotating stellar photosphere. The variations of the RV are characterized and analyzed according to the stellar inclination, the latitude and the number of spots. The Lomb-Scargle periodograms of the RV variations induced by activity present power at the rotational period Prot of the star and its two- rst harmonics Prot/2 and Prot/3. Three adjusted sinusoids  xed at the fundamental period and its two- rst harmonics allow to remove about 90% of the RV jitter amplitude. We apply and validate our approach on four known active planet-host stars: HD 189733, GJ 674, CoRoT-7 and ¦É Hor.
%U http://dx.doi.org/10.1051/epjconf/20101102005